can you explain to me in detail what is feature vector like what details does it extracts from executable
No, I can't. One, I am not sure if some (all?) of the information is public, and two, the information we extract is changing constantly.
how long does it take for cloud to analyze new behavior and classify it as malicious
Sometimes it can be done automatically, and then it is fast, sometimes it needs manual resolution, and then it can be a bit slower.
I am sorry I cannot provide you with anything truly specific